Lining for furnaces



May 3, 1932. R P. SOUTH LINING FOR FURNACES INVENTOR Filed March 22,1929 Patented May 3, 1932 UNITED STATES PATENT OFFICE- RICI-IARD P.SOUTH, F CLEVELAND, OHIO, ASSIGNOR T0 LAVA CRUCIBLE COMPANY OFPITTSBURGH, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENN- SYLVANIALINING 'FOR FURNACES Application inea March 22, 1929. seriaifno.349,169. y Y

This invention relates to linings for furnaces or the like, and moreparticularly to metal melting furnaces of the cylindrical horizontallydisposed rotatable type, wherein slag is formed during the meltingoperation and in which the melting is effected by heat from an oil orgas blast passing over the contained metal or by heat from an electricarc.

The linings for such furnaces as heretofore employed have been thesource of considerable trouble on account of the high temperatures,particularly above the molten metal, and the action of the metal andslag on the lining.

The prime object of the present invention is to provide a cylindricalfurnacelining of the character specified, comprising a portion formed ofa high temperature-resistant refractory, and a lower or metal-receivingportion formed of a slag resistant and chemicalresistant refractory.

Additional objects will become apparent from the following descriptiontaken in connection with the accompanying drawings, wherein:

Fig l is a longitudinal vertical sectional View ofV a cylindricalfurnace embodying my invention;

Fig. 2, a sectional view taken at right angles to the view of Fig. 1;and

Fig. 3, a'view similar to Fig. 2, showing a inodied form of furnace.

Referring to the drawings, the furnace in general comprises acylindrical metal casing 5 provided with a cylindrical lining 6. Casing5 is separated from said lining by a layer of insulating material 7,such as fire clay or the like.

As shown and as preferred, the lining body 6 is an integral unit formedof two materials, the upper portion A being formed of a refractorymaterial having a high temperature resistance, and the lower portion Bformed of a slag resistant and chemicalresistant refractory material;For example,

the portion A may be formed of silicon carbide and the lower portion Bof mullite.

' At' its ends, the lining body 6 is provided with'annular recesses 8 toreceive circular end pieces 9 constituting portions of the liningportions 8a entered inthe respective recesses and secured by a layer ofcement or fire clay lO. The ,end pieces 9 consist of an uppertemperature-resisting portion A and a lower slag or chemical-resistingportion B', and are further-each provided with a central opening 1l toreceive hollow trunnions 12. The

furnace'is mounted in any suitable mannerV to permit rotation thereof onthe said trun-` nions. f

The construction describedV is typical ofthe cylindricalor barrel-shapedfurnace used in practice, principally forv melting brass or bronze. Insome types, as shown inthe drawings, electrodes 13 are introducedthrough the hollow trunnions 121:0 yproduce an electric arc i by arefractory door, held in place by clamping and sealed with fire clay inthe usual manner.

' During vthe melting,k operation, the molten metal will kbe in contactwith the lower lining portions B and B of the body and the end pieces,which, due to their slag and/or chemical-resisting properties, willpreventfdestruction thereof. The upper liningportions A and A willwithstandthe high temperatures of the process because of theirrefractory properties. Thus, the-objectionable chemical action of theslag Vin the usual type of lining is not present and the region ofhighest c u n o u said end pieces having annular projecting linVtemperature is protected by portions A and A. Y

Y Upon completing the melting process, the furnace may be rotated onitstrunnions 12 to discharge the molten metal.V

In the form of Fig. 3, the furnace casing 5a is divided horizontally.Such construction provides ease of assembly, for the lining 6a may besecured in the lower half of the furnace before assembling the upperhalf of the casing. This form of furnace is further provided with anopening 14a in the top thereof, for charging and pouring.

It will be seen that such a furnace lining willrgive ent-ended service,lessen the frequency of shut-downs, and willprovide a lining easilychangeable. Y

Various changes and modifications are contemplated, provided they fallwithin the scope of the following claims.`

Iclaim:V y y l. In a closed cylindrical furnace, a lining comprising acylindrical body and annular end pieces in interiitting engagement withthe Y body, the upper portion of said -c vlindrical i i i body and endpieces formed of a high temperature-resistant refractory and the lowerportion of said body and end pieces coacting to Vheld molten metal andbeing formed of a slag-resistant refractory.

2. In a cylindrical furnace, a one-piece cylindrical lining'member, twoend members cacli iii one piece interfitted into the opposite ends ofthe cylindrical lining member, a portion of each member being resistentto chemical att-ack of slag and jointly forming a holding means formolten metal, and the remainder of each member being of refractorymaterial resi tant to high temperature.

In aY c ndrical furnace, a one-piece cylindrical lining member, two endmembers each in one piece interfittedinto the opposite ends of thecylindrical lining member, a por- .tion of each member being of mulliteand the remainder being` of silicon carbide, and trimiizvons of siliconVcarbide interfitted into the cnd members at the junction of the mulliteyand silicon carbide. Y Y

'In a cylindrical furnace, a olie-piece cyical lining member, two endmembers each in one piece interfitted into the opposite ends of thecylindrical lining member, a portion of each member being of mullitewhereby y closed construction, said furnace having a lining providedwith a discharge opening in a side thereof, said lining being of a formto hold molten Vmetal and being of mullite-to a height above the base ofsaid opening.

. 6, In a cylindrical furnace, a cylindrical lining member, two'endmembers interfitted y RICHARD P. soUTH. y

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